Contingency Planning (further)
Server and a computer system require (electrical) power to run and some events can disrupt this leading to certain consequences for the business and its users/staff. A UPS (uninterruptible power supply) takes away some of these consequences by providing backup power for a short period of time (since it stores it in a battery) but it can be very costly depending on the capacity required. A large capacity one will be able to keep systems up for longer but cost more as a result and vice verse for a smaller capacity one (although still costly). Our is able to keep systems up for about 5 minutes which should be sufficient time for staff/users to save and shut down before any data is lost. If staff/users weren't given this chance then valuable data could be lost and the hardware could be damaged from the sudden shut down of a power cut because the data (for example a document a user was creating/editing without saving) would be stored in the RAM which only operates while able to draw power. This website has links/tags to many articles you may find useful with regards to UPS: https://www.upspower.co.uk/ups-installation/ Servers are expensive so having a backup doubles costs since you have to pay the initial hardware cost and the power cost to keep it up and running, The reason for it being up and running with the other is that there isn't a delay when switching between servers so staff/users can continue to work. It also means we know for sure that one isn't broken as if it is not running we don't know. The more backup servers the higher the costs but the less likely the system will have to go down since both servers could break at the same time or one could break while the other is being fixed from a previous issue. We have to strike a balance between the cost of running additional backup servers and the cost of the system going down. VMware is a company that allows you to copy data on a virtual machine (VM) in a virtual environment to back up data, preventing data loss. Virtualization is where you run two or more operating systems on one physical PC (personal computer). Here's a link to a company that used VMware backup instead of physical to save money and reduce physical server footprint: https://www.computerweekly.com/tip/Data-backup-and-recovery-software-A-financial-services-case-study RAID (Redundant Array of Independent Disks) is a method of storing data on multiple drives. There are multiple types but the some of the most common are 0, 1 and 10. RAID 0 is setup so that the data is sorted into blocks that are striped (spread) across the drives, which allows the data to be read from 2 drives at once which improves performance/speed at the cost of a lack in redundancy which could be very costly when handling mission critical processes. RAID 1 duplicates the data across both drives which means you won't lose any data if one drive fails, however the amount of system storage you have is halved. RAID 10 combines both methods where 2 RAID 1 setups are combined in RAID 0 which means up to two drives can be lost before any data is lost and speed/performance is faster but this does come at a higher financial cost. Backup sites can be hot, warm, cold and mobile (hot). Hot sites are a complete duplicate of the current system with hardware/software/data but also carry the same cost where you have to buy double the equipment. Mobile hot sites are the same as a regular hot site with the difference being it is on the move which is more secure as hackers will find it harder to locate it but as well as doubling costs, vehicular costs will also need to be taken making it extremely expensive and only used by larger companies. Cold sites are simply a space you have available that allows you to move everything to the new site (hardware/software/data/racks) and as a result are much cheaper than the other methods however it takes longer to get up and running (assuming you get all hardware/software/data to it) which makes it a bad option when handling mission critical (crucial to keep the business running) work. Warm sites strike a balance between hot and cold which make them a good backup site while not being too expensive for our company to own. When contingency planning you have to consider whether it is mission critical and whether it will affect the business/cause a loss of revenue and will that loss in revenue be higher than the cost of a better backup site (hot site for instance). For example, if a fire spread across the building making it unusable, if a backup site wasn't available the business couldn't run and may shut down as a result whereas if a backup site is used then the business should still be able to run (after some delay). https://www.youtube.com/watch?v=xWTbPY0OfB0